It is known from the prior art that the dielectric materials for a printed circuit board are present as structured or unstructured foil. In the first case (structured), the material flows around the components mounted on the substrate during heating and pressing and encloses them. In the second case (unstructured), the foils are placed via recesses therein over the components. If very thin components are involved, the components can be pressed directly into said foil.
If thicker components are involved, the dielectric must be pre-routed. Furthermore, in order to enclose the components entirely, it is usually necessary to work with a plurality of dielectric foils disposed one above the other.
It is disadvantageous that the material flows into the recess during pressing, thereby surrounding the components entirely. In the cases in which the volume of the cavity is so great that the quantity of material is insufficient to fill the cavity, additional liquid material is poured into the cavity, and so less material from the foil material is required.
In another known method, semiconductor processes (for example “spin coating”) are used to apply liquid dielectrics in a planar manner. Said methods are also used for embedding one or more chips. Only relatively thin thicknesses of less than 20 μm are possible, however. Greater thicknesses, which can be attained by, for example, screen printing or knife-coating, are not possible.
U.S. Publication No. 2008/0123318 describes a method for assembling a printed circuit board. In that case, a substrate which comprises recesses is positioned on a vacuum plate. After components have been inserted into the recesses, the open cavities of the recesses are filled with an adhesive in order to affix the components. Subsequent thereto, after the vacuum plate has been removed, a metal film is applied to a front side and to a back side of the substrate.
Proceeding from the prior art, a problem to be solved is therefore that of dielectrically embedding the components without allowing unnecessary forces to act thereon, and without the need to pre-route a foil. Furthermore, the method should enable components of different sizes and thicknesses to be enclosed simultaneously.
The present invention is directed at overcoming one or more of the above-identified problems.